Have you had a look on the Global Gateway? If you register your school, you can then have a look around at all the French-speaking schools that are seeking a link in this country. www.globalgateway.org.uk
Does your town have a French twin town? You could maybe seek a link that way.

I have successfully used www.etwinning.net this year with a school in Spain. You establish an e-mail project and set up a twinspace. training is available to be able to do this, but it's not very difficult.